Newbie Question regarding Audio-Looping

MusE is a MIDI/Audio sequencer with recording and editing capabilities, aiming to be a complete multitrack virtual studio for Linux. https://muse-sequencer.org/

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TheYke
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Newbie Question regarding Audio-Looping

Post by TheYke »

Hey there, just checking muse out for the first time ...
spent half of the day to troubleshoot one issue which is holding me back. Sorry if it's something very basic I've overlooked but couldn't find any info about this so far:

When I loop an audio-clip it plays through fine the first time, but then it goes silent until I place the playhead manually before the audio-clip again.
Am I missing something basic here?

greets

EDITS: typos and stuff

Tim E. Real
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Re: Newbie Question regarding Audio-Looping

Post by Tim E. Real »

If you are using the latest release, be sure Global Settings -> 'latency correction' is turned off.
There is a bug that looping audio does not work with latency correction enabled.

Beyond that, I have not noticed any problems, looping works OK here during a quick test - with latency correction off.

Be sure the two blue markers are placed at the beginning and ending of the desired loop, and make sure the looping button is on.
Should work...

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TheYke
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Re: Newbie Question regarding Audio-Looping

Post by TheYke »

regarding latency compensation: as long it's not checked in global settings, it's no poblem if I have latency-settings set inside jack-configuration?
Or should they be on zero, too?

Heres what I do:
I add a synth-track
I add a midi-track to play it
I add a wave-track and route the audio from the synth track to it
I record audio on the wave-track.
I set the loop brackets with mouse-middle-click for the left one, right for the right one, enable loop
hit play

No latency-compensation option set, current github-master branch :?

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oscillator
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Re: Newbie Question regarding Audio-Looping

Post by oscillator »

I can confirm that when looping, the audio track is only played the first time, not on consecutive repeats. This is regardsless of if the audio track starts inside the loop or before.

This is with latency compensation OFF. I even toggled it on then off as I remembered that spamatica reported an issue with the switch (on the issue tracker).

Muse 3.1.0.
MusE DAW running on Debian 10 Stable/XFCE4.
https://oscillator.se/musik

Tim E. Real
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Re: Newbie Question regarding Audio-Looping

Post by Tim E. Real »

it's no poblem if I have latency-settings set inside jack-configuration?
Correct. Our latency settings have no bearing on the Jack configuration port latency settings.
You may leave them alone when our setting is off.
When our setting is on, we do use those Jack values, indirectly, since they are included in any
port latencies reported to us by Jack.
So yes those Jack settings are important, but only when our latency correction is on. They tell Jack (and MusE)
the small amount of final inherent hardware latency which cannot easily be known, the user must enter the actual amount
as measured say with jack_iodelay.

Side note, I was considering how we might build jack_iodelay into MusE to make things easier for the user.
I hope to (somehow) add extra entry boxes in MusE (somewhere) for user additional latency values, where they might enter those values.

On a final note, I need to point out that one small section was not completed yet:
The part where Jack asks us the grand total latency from our Jack input ports to our Jack output ports.
To another outside Jack client, it will always look as though MusE has zero contribution to latency from
all of its Jack input ports to all of its Jack output ports.
Which is not correct. I need to submit the correct information to Jack.


Now... the wave thing: How to proceed? Hm.
Can't seem to reproduce it here.
Possible for you to post an example test med file and wave file?
At least I can examine the marker points and so on. Even without the wave file it might possibly help.

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TheYke
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Re: Newbie Question regarding Audio-Looping

Post by TheYke »

thanks for the quick answer!
for sure ...: this is a .med file I just created. the wav file is the one which was "resampled" from a zynaddsubfx synth-track.

File was too big for an attachment, here is a link https://ufile.io/jgfn13mh

Tim E. Real
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Re: Newbie Question regarding Audio-Looping

Post by Tim E. Real »

Thanks for the files!
I tried at 44100 and 48000 Jack sample rates.

I tried to get it to happen but no luck.

I let it play and went out for some socially distant food.
Still playing.

However, there is one thing that made it happen:
If the tempo is adjusted while looping, that may mess it up.
If I hit the 200% tempo button and then back to N normal, MusE does not recover and there's no sound and stop must be pressed.
By any chance are you guys adjusting tempo while playing? Probably not, eh?

I'll keep trying...

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TheYke
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Re: Newbie Question regarding Audio-Looping

Post by TheYke »

Hmm no not really ... was only playing around with the very basic stuff, as always when I'm trying to learn a new DAW: create some clips, load a synth, check how to move the loop brackets, and basic routing.
Too bad, because I like the layout of the UI and the app seems to be quite responsive. Would love to try and make some beats with it.

EDIT: aaaahhh I guess, I got it now working: It seems that you have to turn on jack-transport, then it works. without jack-transport enabled it just plays one time. Should it be like that? Any insight on this?

Tim E. Real
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Re: Newbie Question regarding Audio-Looping

Post by Tim E. Real »

Confirmed ! Houston, we have a bug !

Except... it's backwards from what you say.
I did not notice your song has Jack Transport turned off. It played just fine.
Then after your last post edit, I turned Jack Transport on, and boom - bug.
It causes messed up sound no matter what. Playing with the blue markers helps somewhat but no, it's messed up.
As soon as I turn off the transport again, it goes back to working, although sometimes it requires a stop first.
@TheYke @oscillator Can I get verification of that behaviour, before I ask for an issue report? Thanks.

You should notice messages in a terminal similar to these.
When you got 'em you got trouble, if not then all should be OK:
fifo get(Track 3) (B) error expected 431485, got 383485
FIFO 0x851c4c0 underrun
WaveTrack::getPrefetchData(Track 2) (prefetch peek B) fifo underrun
This is quite odd, Jack Transport doing this, and our built-in transport does not. [Sigh...]
When Jack Transport is off, MusE uses a built-in transport instead.
Which is possible evidence that (off the top of my head) I may have caused this when I added that fourth button 'Timebase Master',
which basically is only enabled when using Jack Transport.
That 'feature' is in release 3.1.0. See ChangeLog 06.12.2019 and followup 08.12.2019.

Thanks for spotting this. I had no idea that was happening.

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TheYke
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Re: Newbie Question regarding Audio-Looping

Post by TheYke »

Tim E. Real wrote:
Thu Apr 30, 2020 8:24 am

You should notice messages in a terminal similar to these.
When you got 'em you got trouble, if not then all should be OK:
fifo get(Track 3) (B) error expected 431485, got 383485
FIFO 0x851c4c0 underrun
WaveTrack::getPrefetchData(Track 2) (prefetch peek B) fifo underrun
I can confirm that I saw a message like this, yesterday, but it seems I cannot reproduce it now.

Odd: for me looping works if the state of jack-transport looks like:
jack_transport1.jpg
(means on, doesn't it?)
and the problem occurs when button looks like
jack_transport2.jpg
(means off (?)).

greets

EDIT: typos
You do not have the required permissions to view the files attached to this post.

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oscillator
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Re: Newbie Question regarding Audio-Looping

Post by oscillator »

Yeah @Tim E. Real , I can confirm that when I turn Jack Transport On it works!

Tomorrow it is the 1st of May. In these Corona-times, I can appreciate even more that we work together towards a common and better world! :)
MusE DAW running on Debian 10 Stable/XFCE4.
https://oscillator.se/musik

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